From patchwork Wed Apr 15 14:32:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mauro Carvalho Chehab X-Patchwork-Id: 1271217 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-ext4-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=kernel.org Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=default header.b=AP+f0Gmv; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 492Q305rxPz9sT3 for ; Thu, 16 Apr 2020 00:38:52 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2894372AbgDOOit (ORCPT ); Wed, 15 Apr 2020 10:38:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:45454 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2394080AbgDOOdD (ORCPT ); Wed, 15 Apr 2020 10:33:03 -0400 Received: from mail.kernel.org (ip5f5ad4d8.dynamic.kabel-deutschland.de [95.90.212.216]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9150121D7E; Wed, 15 Apr 2020 14:32:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586961171; bh=8XWaSPQEn2foEpJeuRzmwtKfRSy0jcH1jiL1DK6qlto=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AP+f0GmvQ6G0JBFmdKJqZshPjHodSus0vbl5J9sBS9owW+n7b0zrdxk8xFyNAesV5 h+xIAakhmIVrieT1xjBycxZzwICap5J9XK9ksadIen6XF85K70JTbLtXmKazT593He r7jVCWLjqIEsinUQiPR5uZO5srTuMjowi/fCqq0A= Received: from mchehab by mail.kernel.org with local (Exim 4.92.3) (envelope-from ) id 1jOj5t-006kOe-DB; Wed, 15 Apr 2020 16:32:49 +0200 From: Mauro Carvalho Chehab To: Linux Doc Mailing List Cc: Mauro Carvalho Chehab , linux-kernel@vger.kernel.org, Jonathan Corbet , Jan Kara , linux-ext4@vger.kernel.org Subject: [PATCH 12/34] docs: filesystems: convert dax.txt to ReST Date: Wed, 15 Apr 2020 16:32:25 +0200 Message-Id: <71b1f910b2c3569a9fdaa8778378dd734f4f0091.1586960617.git.mchehab+huawei@kernel.org> X-Mailer: git-send-email 2.25.2 In-Reply-To: References: MIME-Version: 1.0 Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org - Add a SPDX header; - Adjust document title; - Some whitespace fixes and new line breaks; - Add it to filesystems/index.rst. Signed-off-by: Mauro Carvalho Chehab --- Documentation/admin-guide/ext4.rst | 2 +- Documentation/filesystems/{dax.txt => dax.rst} | 9 +++++++-- Documentation/filesystems/ext2.rst | 2 +- Documentation/filesystems/index.rst | 1 + 4 files changed, 10 insertions(+), 4 deletions(-) rename Documentation/filesystems/{dax.txt => dax.rst} (97%) diff --git a/Documentation/admin-guide/ext4.rst b/Documentation/admin-guide/ext4.rst index 9443fcef1876..103bcc345bad 100644 --- a/Documentation/admin-guide/ext4.rst +++ b/Documentation/admin-guide/ext4.rst @@ -392,7 +392,7 @@ When mounting an ext4 filesystem, the following option are accepted: dax Use direct access (no page cache). See - Documentation/filesystems/dax.txt. Note that this option is + Documentation/filesystems/dax.rst. Note that this option is incompatible with data=journal. Data Mode diff --git a/Documentation/filesystems/dax.txt b/Documentation/filesystems/dax.rst similarity index 97% rename from Documentation/filesystems/dax.txt rename to Documentation/filesystems/dax.rst index 735f3859b19f..5838144f80f0 100644 --- a/Documentation/filesystems/dax.txt +++ b/Documentation/filesystems/dax.rst @@ -1,5 +1,8 @@ +.. SPDX-License-Identifier: GPL-2.0 + +======================= Direct Access for files ------------------------ +======================= Motivation ---------- @@ -46,6 +49,7 @@ stall the CPU for an extended period, you should also not attempt to implement direct_access. These block devices may be used for inspiration: + - brd: RAM backed block device driver - dcssblk: s390 dcss block device driver - pmem: NVDIMM persistent memory driver @@ -55,6 +59,7 @@ Implementation Tips for Filesystem Writers ------------------------------------------ Filesystem support consists of + - adding support to mark inodes as being DAX by setting the S_DAX flag in i_flags - implementing ->read_iter and ->write_iter operations which use dax_iomap_rw() @@ -127,6 +132,6 @@ by adding optional struct page support for pages under the control of the driver (see CONFIG_NVDIMM_PFN in drivers/nvdimm for an example of how to do this). In the non struct page cases O_DIRECT reads/writes to those memory ranges from a non-DAX file will fail (note that O_DIRECT -reads/writes _of a DAX file_ do work, it is the memory that is being +reads/writes _of a DAX ``file_`` do work, it is the memory that is being accessed that is key here). Other things that will not work in the non struct page case include RDMA, sendfile() and splice(). diff --git a/Documentation/filesystems/ext2.rst b/Documentation/filesystems/ext2.rst index d83dbbb162e2..fa416b7a5802 100644 --- a/Documentation/filesystems/ext2.rst +++ b/Documentation/filesystems/ext2.rst @@ -24,7 +24,7 @@ check=none, nocheck (*) Don't do extra checking of bitmaps on mount (check=normal and check=strict options removed) dax Use direct access (no page cache). See - Documentation/filesystems/dax.txt. + Documentation/filesystems/dax.rst. debug Extra debugging information is sent to the kernel syslog. Useful for developers. diff --git a/Documentation/filesystems/index.rst b/Documentation/filesystems/index.rst index c4f95f76ba6a..8e3ccb4ed483 100644 --- a/Documentation/filesystems/index.rst +++ b/Documentation/filesystems/index.rst @@ -24,6 +24,7 @@ algorithms work. splice locking directory-locking + dax automount-support